Automatic rhythm device with start and stop controller for clock oscillator and a gate

ABSTRACT

An automatic rhythm device incorporated in an electronic musical instrument comprises as a conventional construction, a clock pulse oscillator, a multistage frequency dividing counter chain, a rhythm pattern pulse encoding matrix, rhythm selector switches, rhythm sound sources and a rhythm sound reproducing system arranged in the order mentioned; and as an additional construction, a normally nonconducting gate circuit coupled between the sound sources and the sound reproducing system and a rhythm start and stop controller which includes a two-way switch operated by a player during performance for an organ section of the instrument and a bistable circuit having two halves alternately brought to reverse positions by the operation of the switch thereby to produce a control signal for alternately starting or stopping the oscillation of the clock oscillator in response to the operation of the switch as well as for causing the gate circuit alternately to be conducting or non-conducting. The device constituting a rhythm section for the musical instrument enables the start and termination of rhythm sounds without failure.

United States Patent 1191 Hirano Apr. 16, 1197 1 [54] AUTOMATIC RHYTHM DEVICE WITH 3,646,242 2/1972 Okamoto 84/1.03 START N STOP CONTROLLER FOR 3,707,594 12/1972 lchikawa 84/1.03

CLOCK OSCILLATOR AND A GATE Primary Examiner-Richardson B. Wilkinson [75] Inventor: Katsuhiko I-Iirano, Hamakita, Japan Assistant Emminer stanley Witkowski 73] Assignee: Nippon Gakki Seizo Kabushiki Attorney, Agent, or Firm-Kem0n, Palmer Kaisha, I-Iamamatsu-shi, Shizuoka, rook Japan 22] Filed: Apr. 17,1973 [57] B I F An automatic rhythm dev1ce incorporated m an elec- [2]] Appl' 351979 tronic musical instrument comprises as a conventional construction, a clock pulse oscillator, a multistage fre- [30] Foreign Application Priority Data quency dividing counter chain, a rhythm pattern pulse APL 19 1972 Japan u v 47 O46386 encoding matnx, rhythm selector switches, rhythm i sound sources and a rhythm sound reproducing system [52 U.S. Cl. 84/1 03 I arranged in the order mentioned; and as an additional ['51] Int. Cl. G10h 1/00 Construction a normally nonconducfing gate circuit [58] Field of Search 84/1.01 1.03 1.17 1.24 between the Smmd and i producing system and a rhythm start and stop controller which includes a two-way switch operated by a [56] References Cited player during performance for an organ section of the instrument and a bistable circuit having two halves al- UNITED STATES PATENTS ternately brought to reverse positions by the operation Hlyama N of the witch thereby to produce a control signal for g gfi 22 alternately starting or stopping the oscillation of the 941973 2251? 84x03 clock oscillator in response to the operation of the 37633O5 10/1973 'g 'gi 84/1'03 switch as well as for causing the gate circuit alter- 3,358,068 12/1967 Campbellmjull :1: 84/1301 lately be conducting or .521 969 Park 1 84/ 1.03 The device constituting a rhythm section for the musical instrument enables the start and termination ennes et a r of rh thm s unds w thout fall r 3,585,891 6/1971 Schwartz et al. 84/l.03 y 0 1 e 3,624,263 11/1971 Uchiyama 84/1.03 3 Claims, 2 Drawing Figures RHYTHM -48 PULSE START a SHAPER STOP H CONTROLLER 1 1 31 13:2 1233 4 [$120 CLOCK STAGE ST AGE STAGE STAGE 220 OSCILLATOR 1 1 2 3 4 1 a 1 .1 1 1 1 1 1 1 f W 1 l 7 E 1 1 1 v I7SOUND souaces 12 i\f fg. i ;Q A S M 1 E g g D D1 L I 1 VR A A, s E RH3 ,1.

f3 1 g *T 7 W ,3} R i 17 s; l w 7 SW 1 M "Wsoumo SOURCES AUTOMATIC RHYTHM DEVICE WITH START AND STOP CONTROLLER FOR CLOCK OSCILLATOR AND A GATE BACKGROUND OF THE INVENTION This invention relates to an automatic rhythm device incorporated in electronic musical instruments and more particularly to an improvement of the rhythm start and stop control arrangement.

Electronic electronic musical instruments such as electronic organs, have recently been more favorably accepted a then they include, in addition to the conventional organ section for playing ordinary musical sounds consisting of melody, chord or bass sounds or combinations thereof upon selective depression of a plurality of manual and/or pedal keys arranged in the order of musical notes, an automatic rhythm device constituting a rhythm section for playing rhythm sounds consisting of percussion instruments (e.g.,

claves, maracas, cymbals, bass drum and snare drum) tronic musical instruments of the prior art includea conventional relay mechanism comprising a coil selectively energized by a two-way switch attached-for lateral movement by a players footto an appropriate performance control member for the organ section, for example, a volume control expression'pedal originally depressed by the players foot during performance and a normally open switch closed by the energization of the coil so as to allow the generation of rhythm sounds from the rhythm section. 7

However, the rhythm start and stop control arrangegate circuit to be alternately conducting or nonconducting as well as a clock oscillator for generating a repetitive basic tempo pulse train for the rhythm section tolbe alternately started or stopped.

The automatic rhythm device of this invention incorporated in an electronic musical instrument has the advantage that the start and termination of the rhythm sounds of the rhythm section are positively initiated or terminated and securely maintained in either state by operating the two-way switch at the start and termination of performance on the organ section, and the device is unaffected by external mechanical shocks since no mechanically contacting switch is used as in the relay mechanisms of the prior art.

BRIEF DESCRIPTION OF THE DRAWING PREFERRED EMBODIMENT OF THE INVENTION FIG. 1 is a schematic block diagram of an automatic rhythm device incorporated in an electronic musical instrument embodying the invention.

Automatic rhythm devices of the prior art generally include a clock pulse oscillator 11 of the free-running oscillation type such as an astable multivibrator provided, for example, with a frequency control element ment using the relay mechanism of the above mentioned construction had the drawback thatthe nor-- mally open switch which should be kept closed during rhythm performance was often unnecessarily opened by an external mechanical shock or vibration with the result, for example, that rhythm sounds from the rhythm section disappeared in the course of a performance. It is therefore the object of this invention to provide an automatic rhythm device incorporated in electronic musical instruments which provide positive control of the operation and non-operation of rhythm sounds from the rhythm section, and which device is unaffected by external mechanical shock.

SUMMARY OF THE INVENTION 12. The clock oscillator 11 1 is designed'to generate a repetitive basic tempo pulse train having a frequency or time width corresponding to the shortest beat unit (generally, a quaver or a semiquaver) required to produce the later described various sets of rhythm pattern pulses. Output'pulses from the clock oscillator 11 are conducted to a multistage frequency dividing counter chain 13 which comprises, in this example, four stage flip-flops or binary counters 1131, 132, 133 and 134 connected to each other in cascade. These binary counters l3l to 134 are operated with frequencies equal to one-half, one-fourth, one-eighth and one sixteenth of that of output pulses from the clock oscillator Ill and are respectively provided with two output lines a-E, b-F, 0-? and d-Z each producing two output pulses indicating the binary ONE and ZERO which are different by in phase. The output pulses from the binary counters 131 to 134 are conducted into a rhythm pattern pulse-encoding matrix 14 of the hereinunder described construction to be converted into various types of rhythm pattern pulse trains such as for waltz, march and rumba.

As is well known to those skilled in the art, the rhythm pattern pulse-encoding matrix 14 is ordinarily constructed of a diode matrix M arranged selectively to connect diodes D to the predetermined crosspoints of a plurality of column lines connected to the two output lines of the binary counters 131 to 134 respectively intersecting a plurality of row lines which are impressed with clock pulses from the clock oscillator II; as is known in this field, as well as of AND logic and OR logic circuits each having inputs connected to the predetermined combirlation of the row lines.

Various sets of rhythm pattern pulse trains delivered from the AND and OR logic circuits in the encoding matrix 14 pass through rhythm selector swtiches 15 selectively operated by a player prior to performance so as to be supplied as trigger signals to the preselected one or more of a plurality of rhythm sound sources RH,, RH; RH, such as those of the cymbals, maracas and claves. Rhythm sounds from the triggered rhythm sound source or sources are supplied to a sound reproducing system '16 including a volume controller VR, an amplifier A and a loudspeaker S so as to be made audible.

The automatic rhythm device of this invention incorporated in an electronic musical instrument is characterized in this that there are further provided a normally nonconducting gate circuit 17 connected between the rhythm sound sources Rl-l to RH, and the sound reproducing system 16, and a rhythm start and stop controller 18 constructed as laterdescribed so as to alternately deliver a signal for rendering the gate circuit 17 conductive or non-conductive as well as for rendering the clock pulse oscillator 11 operative or nonoperative through a pulse shaper 19 when there a reversing switch 20 of a normally open type is closed. Such switch may be attached, to an appropriate performance control member of the instrument, e.g., a volume control expression pedal 21 (perniissibly a knee lever) usually manipulated by lateral movement of the players right foot during a performance.

The rhythm start and stop controller 18 is further provided with a stand-byswitch 22 having a movable contact 22a and two stationary contacts 22b and 22c, and a clamping switch 23 of a normally open type closed at the time when the manipulation of the switch 20 should be rendered non-effective.

FIG. 2 is a practical arrangement of a circuit portion including the rhythm start and stop controller 18 shown in FIG. 1.

The rhythm start and stop controller 18 comprises a stand-by circuit 30 which includes a stand-by switch 22 and a bistable circuit constructed of two groundedemitter transistors Q and having their collectors connected via the corresponding resistors R and R to the power source'terminal 32? as well as to the corresponding stationary contacts 22b and 220 of the switch 22, each of the transistors Q and Q having its base cross-coupled via the corresponding resistors R and R to the collector of the other transistor; a trigger signal source 31 which includes a grounded-emitter transistor Q having its base connected via two series connected resistors R and R and the reversing switch 20 to a positive power source terminal 32? and rendered conductive when the switch 20 is closed; a flip-flop or bistable circuit 33 which includes two groundedemitter transistors Q and Q each having its base crosscoupled to the collector of the other transistor viaa parallel circuit of a resistor and a capacitor with the flip-flop state alternately reversed by an output from the trigger signal source 31, the clamping switch 23 being connected between the collector and emitter of the transistor 0 for clamping the reversible operation 'of the flip-flop 33; an initial condition-setting circuit 34 which includes a grounded-emitter transistor Q having its collector-emitter path connected in parallel with that of the transistor 0:, in the bistable circuit 33 and its base connected via a resistor R, and a forwardly biased diode D to the power source terminal 32F as well as to the collector of the transistor O in the stand-by circuit 30 via a diode D of the indicated polarity, the

movable contact 22a of the stand-by switch 22 being connected to the ground and contacting that one 22!) of the two stationary contacts which is connected to the collector of the transistor 0., during the nonoperating period of the device; and a switching circuit 35 which includes a grounded-emitter transistor Q having its base connected via a resistor R to the collector of the transistor Q, as well as to the collector of the transistor Q in the stand-by circuit via a resistor R and its collector connected via a resistor R to the power source terminal 32?. The gate circuit 17 comprises a field effect transistor Q having a conductivity type complementary to that of the transistors Q, to 0, used in the rhythm start and stop controller 18 and its gate connected to the collector of the transistor 0,, the drainsource path or conduction channel of the field effect transistor O being connected between the rhythm sound sources RH to RH, and the sound reproducing system 16 which have been shown in FIG. 1.

The pulse shaper 19 comprises a differentiation circuit 36 consisting of a capacitor C and a resistor R and an amplifier 37 which includes a grounded-emitter transistor Q having its base connected via a diode D of the indicated polarity to the junction 38 of the resistor R11 with the capacitor C The clock pulse oscillator 11 comprises a relaxation oscillator 39 constructed ofa unijunction transistor (or double base diode) 0 having its emitter connected to the collector of the transistor Q as well as to the junction 40 of the frequency control element 12 with a capacitor C series-connected between the positive power source terminal 32? and a grounded negative power source terminal 32N, the conduction path of the unijunction transistor Q1 across the first and second bases thereof being connected to the positive and negative power source terminals 32? and 32N via resistors R and R,;, respectively; and a flip-flop or frequency divider 41 constructed of two grounded-emitter transistors Q11 and Q12 each having its base cross-coupled to the other transistor collector via a parallel circuit of a resistor and a capacitor and alternatively rendered conductive by an output from the relaxation oscillator 39.

The operation of the automatic rhythm device according to the invention will now be described with reference to the accompanying drawings.

Firstly, let it be assumed that the switches 20 and 23 are left open and the movable contact 22a of the switch 22 contacts the stationary contact 22b. Then in the stand-by circuit 30, the transistor Q becomes conductive and the transistor Q remains nonconductive. Under this condition, the transistor O is made conductive by its base bias circuit including the resistor R and the forwardly biased diode D and in consequence the initial condition of the device represented by the bistable circuit 33 is attained so that the transistor Q is off or nonconducting and the transistor 0;, is on or conducting.

At this time, the transistor Q, is kept conductive by its base breeder circuit including the collector resistor R of the now nonconducting transistor Q the resistors R and R and the collector-emitter path of the now conducting transistor Q Accordingly, the collector potential of the transistor O is substantially equal to the ground potential.

In consequence, the field effect transistor O is made nonconductive, producing no rhythm sound from the device.

Next, when the engagement of the movable contact 22a of the switch 22 is changed over from the stationary contact 22b to the other contact 22c, the stand-by circuit 30 is brought to a reverse condition to make the transistor Q conductive and the transistor 0., nonconductive. Therefore, the transistor O is rendered nonconductive and in consequence its collector potential is equal to the positive power source potential. As the result, the field effect transistor Q is fired to allow rhythm performance sounds to emanate from the device.

Though, at this time, a differentiating wave consisting of a positive-going component and a negative-going component is generated by the differentiation circuit 36, only the positive-going component is supplied through the diode .D and the amplifier 37 to the emitter of the unijunction transistor Q as the undermentioned external trigger signal. That is, the relaxation oscillator 39 including the unijunction transistor Q ordinarily generates repetitively a signal having a frequency determined by the charging-discharging time constant derived from the product of the resistance of the frequency control element 12 and the capacitance of the capacitor C However, when the external trigger signal is supplied to the emitter of the unijunction transistorQ then the transistor Q is forcibly rendered conductive, causing the relaxation oscillator 39 to be started, regardless of the condition of the transistor Q Thus, the rhythm performance from the device is always initiated in exactly timed relationship with the firing of the field effect transistor Q When, under this condition, the reversing switch is closed by the player during performance, then the bistable circuit 33 is set in the reverse condition so that the transistor Q becomes conductive and the transistor Q non'conductive through the now conducting transistor 0 causing the transistor O to be rendered conductive. As a result, as will be apparent from the above description, the rhythm performance from the device is automatically stopped or terminated. Where, in this case, the clamping switch 23 is kept closed, then the bistable circuit 33 is not brought to the reverse position even if the switch 20 is closed as above-mentioned, thereby continuing 'the rhythm performance from the device.

On the other hand, when the reversing switch 20 is again closed by the'player, with the clamp switch 23 kept open, then the bistable circuit 33 is again brought to the above-mentioned original or initial condition,

causing the rhythm performance from the device to be again started.

When the 'stand-by switch 22 is brought back to its original state with the movable contact 22a being in contact with the stationary contact 22b, the operation of the device is stopped.

Accordingly, the automatic rhythm device of this invention when'incorporated in an electronic musical instrument enables the start and termination of rhythm sounds from the device to be positively and securely controlled.

What is claimed is:

1. In an automatic rhythm device incorporated in an electronic musical instrument of the type including a clock pulse oscillator generating a repetitive pulse train of a predetermined frequency, a multi-stage frequency dividing counter chain cascade connected to said clock pulse oscillator, a rhythm pattern pulse encoding matrix connected to the output of each stage of said counter chain to produce a plurality of sets of required rhythm pattern pulse trains, rhythm selector switches coupled to said encoding matrix, a plurality of rhythm sound sources coupled to said rhythm selector switches and each triggered by at least one rhythm pattern pulse train preselected by said selector switches, and a sound reproducing system coupled to said rhythm sound sources for rendering the triggered rhythm sounds audible, the improvement comprising:

a normally non-conducting gate circuit connected between said rhythm sound sources and said sound reproducing system;

a rhythm start and stop controller including a twoway switch operated during performance of the instrument by a player; and

a bistable circuit coupled to said two-way switch, said I bistable having two halves which may be set alternatively in reverse positions by operation of said two-way switch, one half output of said bistable causing said gate circuit to conduct and said clock oscillator to be forcibly started.

2. An automatic rhythm device as claimed in claim 1 wherein said rhythm start and stop controller further includes an initial condition setting circuit which is constructed of a normally conducting active circuit element having its conduction path connected in parallel with said one half of said bistable circuit and rendered nonconductive during rhythm performance.

3. An automatic rhythm device as claimed in claim ll wherein said rhythm start and stop controller further includes a normally open switch coupled with said one half output of said bistable circuit and closed while rhythm performance is freely continued. 

1. In an automatic rhythm device incorporated in an electronic musical instrument of the type including a clock pulse oscillator generating a repetitive pulse train of a predetermined frequency, a multi-stage frequency dividing counter chain cascade connected to said clock pulse oscillator, a rhythm pattern pulse encoding matrix connected to the output of each stage of said counter chain to produce a plurality of sets of required rhythm pattern pulse trains, rhythm selector switches coupled to said encoding matrix, a plurality of rhythm sound sources coupled to said rhythm selector switches and each triggered by at least one Rhythm pattern pulse train preselected by said selector switches, and a sound reproducing system coupled to said rhythm sound sources for rendering the triggered rhythm sounds audible, the improvement comprising: a normally non-conducting gate circuit connected between said rhythm sound sources and said sound reproducing system; a rhythm start and stop controller including a two-way switch operated during performance of the instrument by a player; and a bistable circuit coupled to said two-way switch, said bistable having two halves which may be set alternatively in reverse positions by operation of said two-way switch, one half output of said bistable causing said gate circuit to conduct and said clock oscillator to be forcibly started.
 2. An automatic rhythm device as claimed in claim 1 wherein said rhythm start and stop controller further includes an initial condition setting circuit which is constructed of a normally conducting active circuit element having its conduction path connected in parallel with said one half of said bistable circuit and rendered nonconductive during rhythm performance.
 3. An automatic rhythm device as claimed in claim 1 wherein said rhythm start and stop controller further includes a normally open switch coupled with said one half output of said bistable circuit and closed while rhythm performance is freely continued. 